Centrifugal cream tester



Feb. 19, 1935. R H GARVER I 1,991,925

CENTRIFUGAL CREAM .TESTER Filed Oct. 8, 1931 2 Sheets-Sheet l HAYHEAHVE Fel?. 19, 1935.

R. H. GARVER l CENTRIFUGAL CREAM .TESTER 2 Sheets-Sheet 2 RAYHERVER Filed oct, ,8, 1951 Patented' Feb. 19,' 1935 UNITED STATES PATENT oFFlcE- CENTRIFUGAL CREAM TESTER Ray H. Garver, Hiram, Oho Application catchers, 1931, seal No. 567,747.

ZVClams.n (Cl.`233-26) This inventionrelates to improvements in that type of centrifugal cream testers commercially known as Babcock testers, and has as` its primary object .improvements inY details `ofnconstructon and mode of operationv and control.k

A more, detailed object is' the provision for maximum capacity in a minimum space by apparatus involving a minimum. cost of-production.

VWith these and other objects in view as'will hereinafter in-part become apparent andin part be stated, theinvention includes a centrifuge of star wheel contourhaving test cup supports at the points of the star, and also includesa motor mounted to be` surrounded by the test cups when pendent, 'the motor beingV located betweenv the centrifuge and the base `of the container in'which the centrifuge isY mounted.

Other features and details of the invention will become apparent hereinafter and be subsequently specically pointed out in the appended claims.

:In the accompanyingdrawinga- --Figure 1 is a sectional elevation of -a cream tester embodying the features of the present invention.' y r Figure 2 is a top plan viewY thereof.

Figure 3Y is an enlarged, fragmentary, vertical section through the motor and adjacent parts, parts' being 4seen in elevation and'parts being broken away for the saving of space. S

Referring to th'edrawings by numerals, 1 indicates a. bowl or other container, preferably of metal, such as aluminum, having a detachable cover 2. The cover 2, for convenience andY facility of operation and observation `of the action of the apparatus, ispreferablymade of two parts hinged together at 3, 3, the smaller of the two parts being provided with an appropriate op-Y erating handle or knob 4 to facilitate manual opening and closing when desired. The pendent ange'of the lid or cover 2 is preferably continuous, as seen in Figure 1, and the flange of the smaller sectionl of the cover having the knob 4 overhangs the extended portion of the flange of the other part of the cover, so that the cover is frictionally retained on the rim or collar of the bowl 1 against accidental dislocation. The entire cover, however, is adapted to be ren'ioved when desired, and to facilitate such operation, an appropriate knob or handle 5 is preferably fixed to the cover at the central point thereof. A preferably electrical heating unit 6 is carried by the cover 2, preferably centrally at Vits under face, for facilitating raising and maintaining the temperature within the bowl 1 at any given desired degree.

Bowl 1 is mounted on lan appropriate stand' or base 7, and to that end the bowl 1 is preferably provided Withspaced feet or lugs 8, 8, three such feet 8 being sufficient and -the usual numberemployed, but a greater number may be provided if desired.

'I'he bottom of thebowl lispreferablypr vided .with a central opening, -andupstanding through the said opening is the housing 9 of an electric motor made up of field laminations and coils 10, `and armature 11 carried bythe shaft 12, which inlturn sustains and actuates the staredge of the shell and preferably' lapping such place 4by, appropriate edge at 18 andY retained in through bolts 19.

The centrifuge 13Yis referred to as star-shaped because vit is made up essentially of a plate so serrated marginally as to produce a series of radiating points 20, 20,k as clearlyseen in Figure 2. Each ofsaid points is, in fact,` an outstanding,

upwardlyl-curve'd arm, 'as best seenv in Figure',"

and as a means of stabilizing each of said arms an appropriate fillet 21 extends along the arm, is preferably formed integral therewith, and is also preferably formed integral with the plate 3. Each arm making up a point of the star is provided with trunniony lugs 22 extending transversely of the respective arm and outstanding at the two sides thereof to receive the usual bails 23 of the test cups 24, there being preferably one test cup 24 arranged betweeneach pair of two adjacent arms of the centrifuge 13. While, forV clearness of disclosure, only a single cup is illustrated, it will be understood that the apparatus involves a set of cups equal to the number of serrations represented by the spaces between the star arms just described. The lcups hang pendent when the apparatus is not in operation, swinging from the trunnions 22 and pivoting about said trunnions as the cups 24 swing outward to an outstanding radial or horizontal position when .the motor is in operation and the centrifuge 13 is revolving at sufficient velocity.

The motor is constructed to consume a relatively moderate starting current and has a resultant moderate torque which is particularly adapted to this type of apparatus for efficient operation and preventing such defects as arise from too sudden acceleration. The loss and injury likely to flow from too sudden acceleration would, of course, be liable to occur With too sudden deceleration. Naturally, the time element frequently is an important factor, and if the stopping of the apparatus is to depend upon mere cutting off of power, the momentum will repre'- sent a substantial delay in having'the apparatus come to a standstill, but, on the other hand, just as'the motor in its'construction provides for a slow and gradual start, provision is here made for a slow and gradual stop while more rapid than the stop that would occur incident to mere loss of momentum. To this end, a brake is provided to effect as rapid slowing down of the centrifuge 13 as may be practicable without'v danger of injury from deceleration. The brake, while susceptible of assuming various forms, ccnsists preferably of a vertically reciprocating rod 27 extending through the housing 9 asia guide, the rod having appropriate slide bearings in the walls of the housing 9; Fixed to' and carried by the upper end portion of rod 27 is a horizontal plate 28, preferably in the form of a disc, but obviouslyY susceptible vof having any of various contours.Y Fixed to the upper face of the plate 28 is an appropriate'brakelining 29. disposedto be lifted to contact with the under surface of the plate making up the centrifuge 13.l The brake isv preferably located spaced as far from the axis of rotation of the centrifuge as practicable while enabling the brake lining 29 to uniformly contact withY an uninterrupted braking surface of the" centrifuge 113. The rod 27 is preferably stressed by a spring 30 in a downward direction to prevent the brake lining 29 from contacting with the under surface of centrifuge 13 except when and as desired by the operator. The spring 30 is preferably located on the rod 2.7 between the bottom wall of housing 9 and the upper nut of a pair of clamping nuts 31,V 31, carried by the lower end of the rod 27. An operating lever 32 extends through an opening in the base `7 and rests on thelower rim thereof, the outer portion of the lever 32v being bent to upstand sufficiently for purposes of operation, and the inner end portion of the lever 32 carrying aispring or other elastic extension '33 extending. between and 33 acting against each other facilitate cushionf ing and gradual taking hold by the friction surface of the brake, and thus the centrifuge is come to a stop by loss of momentum, and'yet no danger is occasioned of injury or loss from too sudden or rapid deceleration. The braking action is accomplished Without jar or shock and with a smoothness comparable with natural loss of velocity except that the centrifuge is brought to a standstill much more quickly.

The housing 9 rests on the base '7 asfdoes the bowl 1,` and the housing 9 snugly fits in the'opening in the bottom of bowl 1, but by preference a draining passage or opening. 34 is provided through the bottom of the bowlv to allow escape cf such liquids as may be spilled within the bowl.

What is claimed isz- 1. In apparatus of the class described, the oombination, with' an electric motor housing having a recess, a Vfield magnet seated in said recess, and anA armature movable relative to and. cooperating withsaid magnet', of `a centrifuge plate connected to be actuated by saidarmature, a brake rod extending through the field magnet and serving to retain the same'in said recess, a brake carried by the brake rod in position for engagi'nga. surface of the centrifuge plate, and elastic means for applyingiandrem'oving' the brake with'respect to said plate.

2. The combination of an electric mota hav- .slowed down much more quickly than if left to ing a housing, a centrifuge plate actuated by' the 

